Solar cell, preparation method thereof and photovoltaic module

Abstract

The embodiment of the invention relates to the photovoltaic field, and provides a solar cell and a preparation method thereof, and a photovoltaic module, the solar cell comprises a substrate having a first surface and a second surface opposite to each other, and the first surface comprises first regions and second regions which are alternately arranged; the first passivation structure is located on the first region and comprises a first passivation layer and a first semiconductor doping layer which are stacked; the second passivation structure is at least located on the second region and comprises a second passivation layer and a second semiconductor doping layer which are stacked; the first surface further comprises a junction region, the junction region comprises a part of at least one of the first region and the second region, the side wall of the first semiconductor doping layer and the side wall of the second semiconductor doping layer are in contact on the junction region, and the junction region is provided with a crystallization doping part; the crystallized doped portion is a portion of at least one of the first semiconductor doped layer and the second semiconductor doped layer. The embodiment of the invention is at least beneficial to improving the hot spot effect of the battery assembly formed based on the solar battery.

Description

Technical Field

[0001] The embodiments of the present disclosure relate to the photovoltaic field, and in particular to a solar cell and a preparation method thereof, and a photovoltaic module. Background Art

[0002] At present, with the gradual depletion of fossil energy, solar cells are increasingly used as a new energy alternative. Solar cells are devices that convert sunlight into electrical energy. Solar cells use the photovoltaic principle to generate carriers, and then use electrodes to lead out the carriers, which is conducive to the effective use of electrical energy. With the maturity and continuous development of PERC cell (Passivated Emitter Rear Cell) technology, it is gradually approaching the theoretical limit of its conversion efficiency. The mainstream technologies currently being promoted include TOPCon cells (Tunnel Oxide Passivated Contact Cell), HIT / HJT cells (Heterojunction Technology Cell), IBC cells (Interdigitated Back Contact Cell), solar thin-film cells and stacked cells.

[0003] However, in the back contact (BC) technology, in order to form a high-efficiency solar cell, the conductivity of the conductive layer in contact with the electrode is often increased as much as possible, and the structural stability of the photovoltaic module formed based on the solar cell is rarely considered comprehensively. Summary of the invention

[0004] The embodiments of the present disclosure provide a solar cell and a method for preparing the same, and a photovoltaic module, which are at least beneficial for improving the hot spot effect of a cell module formed based on a solar cell.

[0005] According to some embodiments of the present disclosure, on one hand, the embodiments of the present disclosure provide a solar cell, comprising: a substrate, the substrate having a first surface and a second surface relative to each other, the first surface comprising a first region and a second region alternately arranged along a first direction; a first passivation structure, located on the first region, the first passivation structure comprising a first passivation layer and a first semiconductor doping layer stacked along the second direction; a second passivation structure, located at least on the second region, the second passivation structure comprising a second passivation layer and a second semiconductor doping layer stacked along the second direction, the doping type of the first semiconductor doping layer and the doping type of the second semiconductor doping layer being different; the first surface also comprises a junction region, the junction region comprising a portion of at least one of the first region and the second region, and the sidewalls of the first semiconductor doping layer and the sidewalls of the second semiconductor doping layer are in contact on the junction region, wherein at least a portion of the junction region has a crystallized doping portion, the crystallized doping portion is a portion of at least one of the first semiconductor doping layer and the second semiconductor doping layer, the crystallized doping portion has a first crystallization rate, the first semiconductor doping layer and the second semiconductor doping layer not located on the junction region have a second crystallization rate, and the first crystallization rate is greater than the second crystallization rate.

[0006] In some embodiments, the junction region is part of the first region, the crystallized doped portion is a portion of the first semiconductor doped layer located on the junction region, and a portion of the first semiconductor doped layer not located on the junction region is an amorphized doped portion.

[0007] In some embodiments, the junction area is part of the second region, the crystallized doped portion is a portion of the second semiconductor doped layer located on the junction area, and the portion of the second semiconductor doped layer not located on the junction area is an amorphized doped portion.

[0008] In some embodiments, the junction area includes a portion of the first area and a portion of the second area; the crystallized doped portion includes a first crystallized doped portion and a second crystallized doped portion, the first crystallized doped portion is a portion of the first semiconductor doping layer located on the junction area, and the second crystallized doped portion is a portion of the second semiconductor doping layer located on the junction area; the portion of the first semiconductor doping layer not located on the junction area is the first amorphized doped portion, and the portion of the second semiconductor doping layer not located on the junction area is the second amorphized doped portion.

[0009] In some embodiments, the first crystallization rate is 10% to 40%, and the second crystallization rate is 0; and / or the grain size in the crystallized doping portion is 5 nm to 30 nm.

[0010] In some embodiments, the ratio of the area of ​​the interface region to the area of ​​the first region is 1% to 30%.

[0011] In some embodiments, the solar cell further includes: a conductive layer, at least located on a portion of the surface of the first passivation structure away from the first surface, and at least located on a portion of the surface of the second passivation structure away from the first surface; a first electrode, disposed on a side of the conductive layer located on the first region away from the first passivation structure; a second electrode, disposed on a side of the conductive layer located on the second region away from the second passivation structure; an insulating layer, located on a portion of the surface of the first passivation structure away from the first surface, and the second passivation structure is also located on a surface of the insulating layer away from the first passivation structure, and there is a gap between the second passivation structure and the first electrode, which is located on the surface of the insulating layer away from the first passivation structure.

[0012] In some embodiments, at least part of the junction area also has a crystallized passivation portion, which is a portion of at least one of the first passivation layer and the second passivation layer. The crystallized passivation portion has a third crystallization rate, and the first passivation layer and the second passivation layer not located on the junction area have a fourth crystallization rate, and the third crystallization rate is greater than the fourth crystallization rate.

[0013] According to some embodiments of the present disclosure, another aspect of the embodiments of the present disclosure further provides a method for preparing a solar cell, comprising: providing a substrate, the substrate having a first surface and a second surface opposite to each other, the first surface comprising a first region and a second region alternately arranged along a first direction; sequentially forming an initial first passivation structure and an initial second passivation structure on the first surface, the initial first passivation structure being located on the first region, the initial first passivation structure comprising an initial first passivation layer and an initial first semiconductor doping layer stacked along the second direction, the initial second passivation structure being located at least on the second region, the initial second passivation structure comprising an initial second passivation layer and an initial second semiconductor doping layer stacked along the second direction The first surface further comprises a junction region, the junction region comprises a portion of at least one of the first region and the second region, and the sidewalls of the initial first semiconductor doping layer and the sidewalls of the initial second semiconductor doping layer are in contact with each other on the junction region; the preparation method further comprises: performing laser crystallization treatment on a portion of at least one of the initial first semiconductor doping layer and the initial second semiconductor doping layer located on the junction region to transform the initial first passivation structure into the first passivation structure, transform the initial second passivation structure into the second passivation structure, and form a crystallized doping portion on at least a portion of the junction region.

[0014] According to some embodiments of the present disclosure, on the other hand, the embodiments of the present disclosure further provide a photovoltaic module, including: a battery string, formed by connecting a plurality of solar cells as described in any of the above items, or formed by connecting a plurality of solar cells formed by any of the above preparation methods; a packaging film, used to cover the surface of the battery string; and a cover plate, used to cover the surface of the packaging film facing away from the battery string.

[0015] The technical solution provided by the embodiments of the present disclosure has at least the following advantages:

[0016] A first passivation structure and a second passivation structure are alternately arranged on the first surface of the substrate to form a back-contact cell. On the one hand, this is conducive to the subsequent formation of two electrodes with different polarities on the first surface based on the first passivation structure and the second passivation structure, so that the electrodes of the solar cell are all arranged on the first surface, and the second surface is not blocked by the electrode, which is conducive to improving the utilization rate of light by the second surface, so that the solar cell has a higher photoelectric conversion efficiency; on the other hand, with the help of the passivation effect of the first passivation structure and the second passivation structure on the first surface, the interface defects and carrier recombination probability of the first surface are reduced, which is conducive to further improving the photoelectric conversion efficiency of the solar cell.

[0017] On this basis, a point where the first passivation structure and the second passivation structure contact each other along the first direction, i.e., the junction area, is defined on the first surface, so that the junction area includes a portion of at least one of the first area and the second area. In other words, at least one of a portion of the first semiconductor doping layer and a portion of the second semiconductor doping layer is located on the junction area, and the junction area is designed to have a crystallized doped portion. Based on this, the crystallized doped portion is a portion of at least one of the first semiconductor doping layer and the second semiconductor doping layer. It is worth noting that the crystallized doped portion has a first crystallization rate, and the first semiconductor doping layer and the second semiconductor doping layer not located on the junction area have a second crystallization rate, and the first crystallization rate is greater than the second crystallization rate.

[0018] In other words, there is a crystallized doped portion between the first semiconductor doping layer not located on the junction area and the second semiconductor doping layer not located on the junction area. Compared with the first semiconductor doping layer and the second semiconductor doping layer not located on the junction area, the first crystallization rate of the crystallized doping portion is higher, and the crystallized doping portion has a smaller square resistance and stronger lateral conductivity. The crystallized doping portion can be used as a local leakage channel between the first semiconductor doping layer not located on the junction area and the second semiconductor doping layer not located on the junction area. Based on the lower second crystallization rate of the first semiconductor doping layer and the second semiconductor doping layer not located on the junction area, the first semiconductor doping layer and the second semiconductor doping layer not located on the junction area have a higher square resistance, which will hinder the lateral conduction of current between the entire first semiconductor doping layer and the entire second semiconductor doping layer, so as to ensure that the solar cell has a higher photoelectric conversion efficiency. In this way, based on the design of the junction area and the crystallized doped part, at least one of the first semiconductor doped layer and the second semiconductor doped layer is partially designed to have strong lateral conductivity, which is beneficial for improving the hot spot effect caused by local shading or defects in the battery component formed based on solar cells by means of the local leakage channel formed based on the crystallized doped part, so as to improve the structural stability of the photovoltaic component. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] One or more embodiments are exemplarily illustrated by pictures in the corresponding drawings, and these exemplified descriptions do not constitute a limitation on the embodiments. Unless otherwise specified, the pictures in the drawings do not constitute a scale limitation. In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the traditional technology, the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 A schematic diagram of a first partial cross-sectional structure of a solar cell provided by an embodiment of the present disclosure;

[0021] Figure 2 A schematic diagram of a second partial cross-sectional structure of a solar cell provided by an embodiment of the present disclosure;

[0022] Figure 3 A schematic diagram of a third partial cross-sectional structure of a solar cell provided in one embodiment of the present disclosure;

[0023] Figure 4 A schematic diagram of a fourth partial cross-sectional structure of a solar cell provided in one embodiment of the present disclosure;

[0024] Figure 5 A fifth partial cross-sectional structural schematic diagram of a solar cell provided by an embodiment of the present disclosure;

[0025] Figure 6 A sixth partial cross-sectional structural schematic diagram of a solar cell provided in an embodiment of the present disclosure;

[0026] Figure 7 A seventh partial cross-sectional structural schematic diagram of a solar cell provided by an embodiment of the present disclosure;

[0027] Figure 8 An eighth partial cross-sectional structural schematic diagram of a solar cell provided by an embodiment of the present disclosure;

[0028] Figures 9 to 16 A schematic diagram of a partial cross-sectional structure corresponding to each step in a method for preparing a solar cell provided in another embodiment of the present disclosure;

[0029] Fig.17 A schematic diagram of a partial three-dimensional structure of a photovoltaic assembly provided by another embodiment of the present disclosure;

[0030] Fig.18 for Fig.17 Schematic diagram of a cross-sectional structure along section A-A1. DETAILED DESCRIPTION

[0031] As can be seen from the background art, the photoelectric conversion efficiency of solar cells and the structural stability of photovoltaic modules formed based on solar cells need to be comprehensively considered.

[0032] The present disclosure provides a solar cell and a method for preparing the same, and a photovoltaic module. In the solar cell, a first passivation structure and a second passivation structure are alternately arranged on the first surface of the substrate to form a back contact cell. On the one hand, it is beneficial to arrange the electrodes of the solar cell on the first surface to improve the utilization rate of the light on the second surface; on the other hand, the interface defects and carrier recombination probability of the first surface are reduced by means of the first passivation structure and the second passivation structure. In this way, the two aspects cooperate to improve the photoelectric conversion efficiency of the solar cell. On this basis, a crystallized doped portion is designed between the first semiconductor doping layer not located on the junction area and the second semiconductor doping layer not located on the junction area. Compared with the first semiconductor doping layer not located on the junction area and the second semiconductor doping layer not located on the junction area, the first crystallization rate of the crystallized doped portion is higher, and the crystallized doped portion has a smaller square resistance and stronger lateral conductivity. In this way, at least one of the first semiconductor doping layer and the second semiconductor doping layer is partially designed to have strong lateral conductivity, which is beneficial for reducing the probability of local overheating when the solar cell is used as a load by means of a local leakage channel formed based on the crystallized doping portion, so as to improve the hot spot effect caused by local shading or defects in the battery assembly formed based on the solar cell, so as to improve the structural stability of the photovoltaic assembly.

[0033] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0034] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0035] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists, A and B exist at the same time, and B exists. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0036] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0037] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0038] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0039] In the accompanying drawings corresponding to the embodiments of the present application, the thickness and area of ​​the layer are magnified for better understanding and ease of description. When describing a component (such as a layer, film, region or substrate) on another component or on the surface of another component, the component can be "directly" located on the surface of the other component, or a third component can be present between the two components. On the contrary, when describing a component on the surface of another component or when another component is formed or provided on the surface of a component, it means that there is no third component between the two components. In addition, when describing a component as "substantially" formed on another component, it means that the component is not formed on the entire surface (or front surface) of the other component, nor is it formed on a partial edge of the entire surface.

[0040] In the description of the embodiments of the present application, when a component "includes" another component, unless otherwise specified, other components are not excluded, and other components may be further included. In addition, when a component such as a layer, a film, a region, or a plate is referred to as being "on / located on" another component, it may be "directly on" the other component (i.e., located on the surface of the other component with no other components between them), or another component may exist in between. In addition, when a component such as a layer, a film, a region, a plate, etc. is "directly located on" another component, or when a component such as a layer, a film, a region, a plate, etc. is located on the surface of another component, it means that no other components are located in between.

[0041] The terms used in the description of the various embodiments described herein are only used to describe specific embodiments and are not intended to be limiting. As used in the description of the various embodiments described and in the appended claims, "the components" are also intended to include plural forms unless the context clearly indicates otherwise. Among them, components include components such as layers, films, regions, or plates.

[0042] The following will describe the various embodiments of the present disclosure in detail with reference to the accompanying drawings. However, it will be appreciated by those skilled in the art that in the various embodiments of the present disclosure, many technical details are provided in order to enable the reader to better understand the embodiments of the present disclosure. However, even without these technical details and various changes and modifications based on the following embodiments, the technical solutions claimed in the embodiments of the present disclosure can be implemented.

[0043] An embodiment of the present disclosure provides a solar cell, which will be described in detail below with reference to the accompanying drawings.

[0044] refer to Figures 1 to 4The solar cell includes: a substrate 100, the substrate 100 has a first surface 110 and a second surface 120 opposite to each other, the first surface 110 includes a first area 130 and a second area 140 alternately arranged along a first direction X; a first passivation structure 101, located on the first area 130, the first passivation structure 101 includes a first passivation layer 111 and a first semiconductor doping layer 121 stacked along a second direction Y; a second passivation structure 102, located at least on the second area 140, the second passivation structure 102 includes a second passivation layer 112 and a second semiconductor doping layer 122 stacked along the second direction Y, the doping type of the first semiconductor doping layer 121 and the second semiconductor doping layer 122 The doping types are different; the first surface 110 also includes a junction area 150, the junction area 150 includes a portion of at least one of the first area 130 and the second area 140, and the sidewalls of the first semiconductor doping layer 121 and the sidewalls of the second semiconductor doping layer 122 are in contact on the junction area 150, wherein at least a portion of the junction area 150 has a crystallized doping portion 103, the crystallized doping portion 103 is a portion of at least one of the first semiconductor doping layer 121 and the second semiconductor doping layer 122, the crystallized doping portion 103 has a first crystallization rate, the first semiconductor doping layer 121 and the second semiconductor doping layer 122 not located on the junction area 150 have a second crystallization rate, and the first crystallization rate is greater than the second crystallization rate.

[0045] It should be noted that Figure 1 A schematic diagram of a first partial cross-sectional structure of a solar cell provided by an embodiment of the present disclosure; Figure 2 A schematic diagram of a second partial cross-sectional structure of a solar cell provided by an embodiment of the present disclosure; Figure 3 A schematic diagram of a third partial cross-sectional structure of a solar cell provided in one embodiment of the present disclosure; Figure 4 This is a schematic diagram of a fourth partial cross-sectional structure of a solar cell provided by an embodiment of the present disclosure. In addition, Figures 1 to 4 In the figures, the crystallized doped portion 103 is indicated by a thicker dotted line.

[0046] In addition, the first direction X is the length direction or the width direction of the solar cell; and the second direction Y is the thickness direction of the solar cell.

[0047] It is worth noting that the first surface 110 defines a point where the first passivation structure 101 and the second passivation structure 102 contact along the first direction X, i.e., the junction area 150, so that the junction area 150 includes a portion of at least one of the first area 130 and the second area 140. Moreover, the first semiconductor doping layer 121 and the second semiconductor doping layer 122 have a contact interface along the first direction X, and the sidewall of the first semiconductor doping layer 121 and the sidewall of the second semiconductor doping layer 122 are designed to contact on the junction area 150, then the contact interface between the first semiconductor doping layer 121 and the second semiconductor doping layer 122 is located on the junction area 150, so that at least one of a portion of the first semiconductor doping layer 121 and a portion of the second semiconductor doping layer 122 is located on the junction area 150. It should be noted that the positional relationship between the first semiconductor doping layer 121 and the second semiconductor doping layer 122 and the junction area 150 will be described in detail later, which will not be repeated here.

[0048] Based on this, it is designed that at least part of the junction area 150 has a crystallized doped portion 103, so that the portion of at least one of the first semiconductor doped layer 121 and the second semiconductor doped layer 122 that are in contact with each other on the junction area 150 is the crystallized doped portion 103, and the crystallized doped portion 103 has a first crystallization rate, and the first semiconductor doped layer 121 and the second semiconductor doped layer 122 that are not located on the junction area 150 have a second crystallization rate, and the first crystallization rate is greater than the second crystallization rate. In other words, it is designed that at least one of the first semiconductor doped layer 121 and the second semiconductor doped layer 122 is partially crystallized to form the crystallized doped portion 103, and the portions of the first semiconductor doped layer 121 and the second semiconductor doped layer 122 that are not located on the junction area 150 are all amorphous portions.

[0049] In this way, compared with the first semiconductor doping layer 121 not located on the junction area 150 and the second semiconductor doping layer 122 not located on the junction area 150, the first crystallization rate of the crystallized doping part 103 is higher, and the crystallized doping part 103 has a smaller square resistance and a stronger lateral conductivity. The crystallized doping part 103 can be used as a local leakage channel between the first semiconductor doping layer 121 not located on the junction area 150 and the second semiconductor doping layer 122 not located on the junction area 150, so as to promote the carriers to be transmitted laterally in the crystallized doping part 103 along the first direction X, increase the recombination probability of the carriers in the crystallized doping part 103, and reduce the probability of local overheating when the solar cell is used as a load. Moreover, since the second crystallization rates of the first semiconductor doping layer 121 and the second semiconductor doping layer 122 not located on the junction area 150 are lower, the first semiconductor doping layer 121 and the second semiconductor doping layer 122 not located on the junction area 150 have a higher square resistance, which will hinder the lateral conduction of current between the entire first semiconductor doping layer 121 and the entire second semiconductor doping layer 122. In other words, carriers can be transmitted laterally along the first direction X in the crystallized doping portion 103, but cannot be laterally conducted between the first semiconductor doping layer 121 not located on the junction area 150 and the second semiconductor doping layer 122 not located on the junction area 150 by means of the crystallized doping portion 103, thereby ensuring that the solar cell has a higher photoelectric conversion efficiency.

[0050] It can be seen that based on the design of the junction area 150 and the crystallized doping part 103, it is beneficial to make at least one of the first semiconductor doping layer 121 and the second semiconductor doping layer 122 partially designed to have strong lateral conductivity, and make the first semiconductor doping layer 121 not located on the junction area 150 and the second semiconductor doping layer 122 not located on the junction area 150 not be laterally conductive, thereby helping to ensure that the solar cell has a high photoelectric conversion efficiency while reducing the probability of local overheating when the solar cell is used as a load, so as to improve the hot spot effect caused by local shading or defects in the subsequent battery module formed based on the solar cell, so as to improve the structural stability of the photovoltaic module, thereby improving the reliability and life of the solar cell and the photovoltaic module.

[0051] It should be noted that, based on the different positional relationships between the first semiconductor doping layer 121 and the second semiconductor doping layer 122 and the boundary area 150, the relationship between the crystallized doping portion 103 and the first semiconductor doping layer 121 and the second semiconductor doping layer 122 is also different. The relationship between the crystallized doping portion 103 and the first semiconductor doping layer 121 and the second semiconductor doping layer 122 will be described in detail later and will not be repeated here.

[0052] In some cases, the first areas 130 and the second areas 140 alternately arranged along the first direction X include the following situations: at least two first areas 130 are arranged at intervals along the first direction X, and at least two second areas 140 are arranged at intervals along the first direction X, one second area 140 is arranged between two adjacent first areas 130, and one first area 130 is arranged between two adjacent second areas 140. In this way, the first surface 110 includes a plurality of boundary areas 150.

[0053] Therefore, at least part of the junction region 150 has the crystallized doped portion 103, including the following two examples: in some examples, each junction region has a crystallized doped portion; in other examples, Figures 1 to 4 , only a portion of the junction regions 150 have the crystallized doped portion 103, and the junction region without the crystallized doped portion is conducive to hindering the lateral conduction of the current between the first semiconductor doping layer 121 and the second semiconductor doping layer 122 in the junction region, further improving the leakage between the first semiconductor doping layer 121 and the second semiconductor doping layer 122, so as to ensure that the solar cell has a higher photoelectric conversion efficiency. It should be noted that Figures 1 to 4 The boundary region without the crystallization doping portion 103 is not shown.

[0054] In some cases, the first surface 110 may be the back side of the solar cell, and the second surface 120 may be the front side of the solar cell. Thus, the first passivation structure 101 and the second passivation structure 102 are alternately arranged on the first surface 110 to form a back-contact cell. On the one hand, this is beneficial for the subsequent formation of two electrodes with different polarities on the first surface 110 based on the first passivation structure 101 and the second passivation structure 102, so that the electrodes of the solar cell are all arranged on the first surface 110, and the second surface 120 is not blocked by the electrode, which is beneficial for improving the utilization rate of light by the second surface 120, so that the solar cell has a higher photoelectric conversion efficiency. On the other hand, with the help of the passivation effect of the first passivation structure 101 and the second passivation structure 102 on the first surface 110, the interface defects and carrier recombination probability of the first surface 110 are reduced, which is beneficial for further improving the photoelectric conversion efficiency of the solar cell.

[0055] It should be noted that, in some examples, the solar cell is a single-sided cell, then the front side of the substrate can be used as a light-receiving surface for receiving incident light, and the back side can be used as a backlight surface. In other examples, the solar cell is a double-sided cell, then both the front side and the back side of the substrate can be used as light-receiving surfaces, both can be used to receive incident light, wherein the front side is the primary light-receiving surface, and the back side is the secondary light-receiving surface. It is worth noting that the backlight surface referred to in one embodiment of the present disclosure can also receive incident light, but the degree of receiving the incident light is weaker than the degree of receiving the incident light by the light-receiving surface, and therefore is defined as a backlight surface.

[0056] The embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings.

[0057] In some embodiments, reference Figures 2 to 4 The solar cell may further include: a conductive layer 107, at least located on a portion of the surface of the first passivation structure 101 away from the first surface 110, and at least located on a portion of the surface of the second passivation structure 102 away from the first surface 110; a first electrode 118, arranged on a side of the conductive layer 107 located on the first region 130 away from the first passivation structure 101; and a second electrode 128, arranged on a side of the conductive layer 107 located on the second region 140 away from the second passivation structure 102.

[0058] In some cases, continue to refer to Figures 2 to 4 The solar cell may further include: an insulating layer 109 located on a portion of the surface of the first passivation structure 101 away from the first surface 110, and a second passivation structure 102 is also located on a surface of the insulating layer 109 away from the first passivation structure 101, and a gap exists between the second passivation structure 102 located on a surface of the insulating layer 109 away from the first passivation structure 101 and the first electrode 118. In other words, the second passivation structure 102 is also located on a portion of the first region 130.

[0059] In one example, continue to refer to Figures 2 to 4 The second passivation structure 102 has a sidewall transitioning from the first region 130 to the second region 140, and the conductive layer 107 may also be located on the sidewall. The conductive layer 107 may include a first conductive layer 117 and a second conductive layer 127, with a gap between the first conductive layer 117 and the second conductive layer 127, the first conductive layer 117 connects the first passivation structure 101 and the first electrode 118, and the second conductive layer 127 connects the second passivation structure 102 and the second electrode 128.

[0060] In some embodiments, the material of the insulating layer 109 may be at least one of silicon nitride or silicon oxide.

[0061] In some embodiments, the conductive layer 107 may be a transparent conductive film, and the materials of the first electrode 118 and the second electrode 128 may be various conductive metals.

[0062] It should be noted that Figures 2 to 4In the figure, only the example in which the second passivation structure 102 is also located on part of the first area 130, and there is an insulating layer 109 between the first passivation structure 101 and the second passivation structure 102 located on the first area 130 is taken. In actual applications, the second passivation structure can be located only on the second area, and the conductive layer can be changed based on the layout change of the second passivation structure, as long as there is a gap between the first conductive layer and the second conductive layer, and the first conductive layer connects the first passivation structure and the first electrode, and the second conductive layer connects the second passivation structure and the second electrode.

[0063] It is worth noting that the specific structure of the crystallized doped portion 103 includes at least the following three embodiments:

[0064] In some embodiments, reference Figure 2 The junction area 150 is part of the first area 130 , the crystallized doped portion 103 is the portion of the first semiconductor doped layer 121 located on the junction area 150 , and the portion of the first semiconductor doped layer 121 not located on the junction area 150 is the amorphized doped portion 104 .

[0065] In this way, only the first semiconductor doping layer 121 is designed to be partially crystallized, so that the first semiconductor doping layer 121 includes a crystallized doping portion 103 and an amorphized doping portion 104, the crystallized doping portion 103 is located on the boundary region 150, and the amorphized doping portion 104 is located on the region of the first region 130 other than the boundary region 150. Moreover, the second semiconductor doping layer 122 at least located on the second region 140 is not crystallized as a whole, and the second semiconductor doping layer 122 as a whole has a second crystallization rate. In other words, the crystallized doped portion 103 is located between the amorphous doped portion 104 and the second semiconductor doping layer 122, and a small amount of carriers collected in the first semiconductor doping layer 121 and the second semiconductor doping layer 122 can migrate to the crystallized doped portion 103 and recombine to form a local leakage channel, but there will be no laterally conductive connection between the amorphous doped portion 104 and the second semiconductor doping layer 122 in the first semiconductor doping layer 121, so as to ensure that a large number of carriers are collected through the first semiconductor doping layer 121 and the second semiconductor doping layer 122 and finally transmitted to the subsequently formed electrodes, respectively. This is beneficial for designing the crystallized doped portion 103 in the first semiconductor doping layer 121 to reduce the probability of local overheating of the solar cell while ensuring that the solar cell has a high photoelectric conversion efficiency, thereby facilitating improvement of the hot spot effect of the battery component subsequently formed based on the solar cell.

[0066] It should be noted that in some cases, continue to refer to Figure 2The second passivation structure 102 is also located on part of the first region 130 , and the junction region 150 also has a second semiconductor doping layer 122 . The second semiconductor doping layer 122 located on the junction region 150 can also be crystallized to form a third crystallized portion 133 . Figure 2 In the figure, not only the crystallized doped portion 103 is divided by a thicker dotted line in the first semiconductor doping layer 121, but also the third crystallized portion 133 is divided by a thicker dotted line in the second semiconductor doping layer 122. In practical applications, only the first semiconductor doping layer located in the boundary region may be crystallized to have a crystallized doped portion.

[0067] In other embodiments, reference Figure 3 The junction area 150 is part of the second area 140 , the crystallized doped portion 103 is the portion of the second semiconductor doped layer 122 located on the junction area 150 , and the portion of the second semiconductor doped layer 122 not located on the junction area 150 is the amorphized doped portion 104 .

[0068] In this way, only the second semiconductor doping layer 122 is designed to be partially crystallized, so that the second semiconductor doping layer 122 includes a crystallized doping portion 103 and an amorphized doping portion 104, the crystallized doping portion 103 is located on the boundary region 150, and the amorphized doping portion 104 is located on the region of the second region 140 other than the boundary region 150. Moreover, the first semiconductor doping layer 121 is not crystallized as a whole, and the first semiconductor doping layer 121 has a second crystallization rate as a whole. In other words, the crystallized doped portion 103 is located between the amorphous doped portion 104 and the first semiconductor doping layer 121, and a small amount of carriers collected in the first semiconductor doping layer 121 and the second semiconductor doping layer 122 can migrate to the crystallized doped portion 103 and recombine to form a local leakage channel, but the amorphous doped portion 104 in the second semiconductor doping layer 122 will not be laterally conductive with the first semiconductor doping layer 121, so as to ensure that a large number of carriers are collected through the first semiconductor doping layer 121 and the second semiconductor doping layer 122 and finally transmitted to the subsequently formed electrodes, respectively, thereby facilitating the design of the crystallized doped portion 103 in the second semiconductor doping layer 122 to reduce the probability of local overheating of the solar cell while ensuring that the solar cell has a high photoelectric conversion efficiency, thereby facilitating the improvement of the hot spot effect of the battery component subsequently formed based on the solar cell.

[0069] It should be noted that Figure 3 In the figure, the crystallized doped portion 103 is divided by a thicker dotted line in the second semiconductor doping layer 122 .

[0070] In some other embodiments, reference Figure 4The junction area 150 includes a portion of the first area 130 and a portion of the second area 140; the crystallized doped portion 103 includes a first crystallized doped portion 113 and a second crystallized doped portion 123, the first crystallized doped portion 113 is a portion of the first semiconductor doping layer 121 located on the junction area 150, and the second crystallized doped portion 123 is a portion of the second semiconductor doping layer 122 located on the junction area 150; the portion of the first semiconductor doping layer 121 that is not located on the junction area 150 is the first amorphized doped portion 114, and the portion of the second semiconductor doping layer 122 that is not located on the junction area 150 is the second amorphized doped portion 124.

[0071] In this way, not only the first semiconductor doping layer 121 is designed to be partially crystallized, but also the second semiconductor doping layer 122 is designed to be partially crystallized, so that the first semiconductor doping layer 121 includes a first crystallized doping portion 113 and a first amorphized doping portion 114, and the second semiconductor doping layer 122 includes a second crystallized doping portion 123 and a second amorphized doping portion 124. In other words, the crystallized doping portion 103 includes a portion of the first semiconductor doping layer 121 and a portion of the second semiconductor doping layer 122. The crystallized doping section 103 is located between the first amorphized doping section 114 and the second amorphized doping section 124. The carriers collected in the first crystallized doping section 113 and the second crystallized doping section 123 can recombine to form a local leakage channel, but there will be no lateral conduction between the first amorphized doping section 114 and the second amorphized doping section 124, so as to ensure that a large number of carriers are collected by the first amorphized doping section 114 and the second amorphized doping section 124 and finally transmitted to the subsequently formed electrodes respectively, thereby facilitating the design of the crystallized doping section 103 in the first semiconductor doping layer 121 and the second semiconductor doping layer 122 to reduce the probability of local overheating of the solar cell while ensuring that the solar cell has a high photoelectric conversion efficiency, thereby facilitating the improvement of the hot spot effect of the battery component subsequently formed based on the solar cell.

[0072] It should be noted that both the first crystallized doped portion 113 and the second crystallized doped portion 123 have a first crystallization rate; both the first amorphized doped portion 114 and the second amorphized doped portion 124 have a second crystallization rate. Figure 4 In the figure, the first crystallized doped portion 113 is divided by a thicker dotted line in the first semiconductor doping layer 121 , and the second crystallized doped portion 123 is divided by a thicker dotted line in the second semiconductor doping layer 122 .

[0073] In some embodiments, the specific structure of the crystallized doping part 103 includes the above three embodiments. Figures 5 to 7At least part of the boundary area 150 also has a crystallized passivation portion 105, the crystallized passivation portion 105 is a portion of at least one of the first passivation layer 111 and the second passivation layer 112, the crystallized passivation portion 105 has a third crystallization rate, the first passivation layer 111 and the second passivation layer 112 not located on the boundary area 150 have a fourth crystallization rate, and the third crystallization rate is greater than the fourth crystallization rate.

[0074] It should be noted that Figure 5 A fifth partial cross-sectional structural schematic diagram of a solar cell provided by an embodiment of the present disclosure; Figure 6 A sixth partial cross-sectional structural schematic diagram of a solar cell provided in an embodiment of the present disclosure; Figure 7 This is a schematic diagram of a seventh partial cross-sectional structure of a solar cell provided by an embodiment of the present disclosure. In addition, Figures 5 to 7 The crystallized doped portion 103 and the crystallized passivation portion 105 are indicated by thicker dotted lines.

[0075] In this way, at least one of the first passivation layer 111 and the second passivation layer 112 is also partially crystallized to form a crystallized passivation portion 105, and the portions of the first passivation layer 111 and the second passivation layer 112 that are not located on the junction area 150 are all amorphous portions. Compared with the first passivation layer 111 that is not located on the junction area 150 and the second passivation layer 112 that is not located on the junction area 150, the third crystallization rate of the crystallized passivation portion 105 is higher, so the crystallized passivation portion 105 has a smaller square resistance and stronger lateral conductivity, and the crystallized passivation portion 105 can be used as a local leakage channel between the first passivation layer 111 that is not located on the junction area 150 and the second passivation layer 112 that is not located on the junction area 150. Moreover, since the fourth crystallization rate of the first passivation layer 111 and the second passivation layer 112 not located on the junction area 150 is lower, the first passivation layer 111 and the second passivation layer 112 not located on the junction area 150 have a higher square resistance, which will hinder the lateral conduction of current between the entire first passivation layer 111 and the entire second passivation layer 112. In other words, carriers can be transmitted laterally along the first direction X in the crystallized passivation part 105, but cannot be transversely conducted between the first passivation layer 111 not located on the junction area 150 and the second passivation layer 112 not located on the junction area 150 by means of the crystallized passivation part 105, thereby ensuring that the solar cell has a higher photoelectric conversion efficiency.

[0076] Based on this, on the basis of designing the crystallized doping part 103, the crystallized passivation part 105 is designed, so that the portion of at least one of the first passivation structure 101 and the second passivation structure 102 located on the junction area 150 is the crystallized part, and the crystallized part includes the crystallized passivation part 105 and the crystallized doping part 103 stacked along the second direction Y, so as to form a local leakage channel in the area where the first passivation structure 101 and the second passivation structure 102 are in contact with each other in the first direction X, so as to further increase the probability of carrier recombination at the junction where the first passivation structure 101 and the second passivation structure 102 are in contact, so as to further reduce the probability of local overheating when the solar cell is used as a load, which is conducive to further improving the hot spot effect in the subsequent battery component formed based on the solar cell.

[0077] In some cases, the first surface 110 includes a plurality of junction regions 150, and at least a portion of the junction regions 150 have a crystallized passivation portion 105, including the following two examples: in some examples, each junction region has a crystallized passivation portion; in other examples, Figures 5 to 7 Only a portion of the junction areas 150 have the crystallized passivation part 105, and the junction area without the crystallized passivation part is conducive to hindering the lateral conduction of the current between the first passivation layer 111 and the second passivation layer 112 in the junction area, further improving the leakage between the first passivation layer 111 and the second passivation layer 112, so as to ensure that the solar cell has a higher photoelectric conversion efficiency. It should be noted that Figures 5 and 6 The boundary region without the crystallization doping portion 103 and the crystallization passivation portion 105 is not shown.

[0078] It is worth noting that, based on the specific structure of the crystallized doped portion 103 including the above three embodiments, the specific structure of the crystallized passivation portion 105 also includes at least the following three embodiments:

[0079] In some embodiments, reference Figure 5 The junction area 150 is part of the first area 130 , the crystallized passivation portion 105 is a portion of the first passivation layer 111 located on the junction area 150 , and the portion of the first passivation layer 111 not located on the junction area 150 is the amorphized passivation portion 106 .

[0080] In this way, only the first passivation layer 111 is designed to be partially crystallized, so that the first passivation layer 111 includes a crystallized passivation portion 105 and an amorphized passivation portion 106. The crystallized passivation portion 105 is located on the interface region 150 like the crystallized passivation portion 105, and the amorphized passivation portion 106 is located on the region of the first region 130 except the interface region 150. Moreover, the second passivation layer 112 at least located on the second region 140 is not crystallized as a whole, and the second passivation layer 112 as a whole has a fourth crystallization rate. Based on this, the crystallized passivation part 105 is located between the amorphous passivation part 106 and the second passivation layer 112, and the carriers will not only recombine in the crystallized doping part 103, but also recombine in the crystallized passivation part 105 of the first passivation layer 111, so as to further increase the recombination probability of the carriers at the contact point between the first passivation structure 101 and the second passivation structure 102, but there will be no laterally conductive connection between the amorphous passivation part 106 and the second passivation layer 112 in the first passivation layer 111, which is beneficial to design the crystallized passivation part 105 in the first passivation layer 111 to further reduce the probability of local overheating of the solar cell while ensuring that the solar cell has a high photoelectric conversion efficiency, which is beneficial to further improve the hot spot effect of the subsequent battery component formed based on the solar cell.

[0081] It should be noted that in some cases, continue to refer to Figure 5 The second passivation structure 102 is also located on part of the first region 130, and the junction region 150 also has a second passivation layer 112 and a second semiconductor doping layer 122. The second passivation layer 112 and the second semiconductor doping layer 122 located on the junction region 150 can also be crystallized to form a third crystallized portion 133 in the second semiconductor doping layer 122 and a fourth crystallized portion 143 in the second passivation layer 112. Figure 5 In the figure, not only the crystallized doped portion 103 is divided by a thicker dotted line in the first semiconductor doping layer 121, and the crystallized passivation portion 105 is divided by a thicker dotted line in the first passivation layer 111, but also the third crystallized portion 133 is divided by a thicker dotted line in the second semiconductor doping layer 122, and the fourth crystallized portion 143 is divided by a thicker dotted line in the second passivation layer 112. In practical applications, only the first semiconductor doping layer located on the boundary region may be crystallized to have the crystallized doped portion, and only the first passivation layer located on the boundary region may be crystallized to have the crystallized passivation portion.

[0082] In other embodiments, reference Figure 6 The junction area 150 is part of the second area 140 , the crystallized passivation portion 105 is the portion of the second passivation layer 112 located on the junction area 150 , and the portion of the second passivation layer 112 not located on the junction area 150 is the amorphized passivation portion 106 .

[0083] In this way, only the second passivation layer 112 is designed to be partially crystallized, so that the second passivation layer 112 includes a crystallized passivation portion 105 and an amorphous passivation portion 106. The crystallized passivation portion 105 is located on the interface region 150 like the crystallized passivation portion 105, and the amorphous passivation portion 106 is located on the region of the second region 140 except the interface region 150. Moreover, the first passivation layer 111 is not crystallized as a whole, and the first passivation layer 111 as a whole has a fourth crystallization rate. Based on this, the crystallized passivation part 105 is located between the amorphous passivation part 106 and the first passivation layer 111, and the carriers will not only recombine in the crystallized doping part 103, but also recombine in the crystallized passivation part 105 of the second passivation layer 112, so as to further increase the recombination probability of the carriers at the contact point between the first passivation structure 101 and the second passivation structure 102, but there will be no laterally conductive connection between the amorphous passivation part 106 in the second passivation layer 112 and the first passivation layer 111, which is beneficial to design the crystallized passivation part 105 in the second passivation layer 112 to further reduce the probability of local overheating of the solar cell while ensuring that the solar cell has a high photoelectric conversion efficiency, which is beneficial to further improve the hot spot effect of the subsequent battery component formed based on the solar cell.

[0084] It should be noted that Figure 6 In the figure, the crystallized doped portion 103 is divided by a thicker dotted line in the second semiconductor doping layer 122 , and the crystallized passivation portion 105 is divided by a thicker dotted line in the second passivation layer 112 .

[0085] In some other embodiments, reference Figure 7 The junction area 150 includes a portion of the first area 130 and a portion of the second area 140; the crystallized passivation portion 105 includes a first crystallized passivation portion 115 and a second crystallized passivation portion 125, the first crystallized passivation portion 115 is a portion of the first passivation layer 111 located on the junction area 150, and the second crystallized passivation portion 125 is a portion of the second passivation layer 112 located on the junction area 150; the portion of the first passivation layer 111 not located on the junction area 150 is the first amorphized passivation portion 116, and the portion of the second passivation layer 112 not located on the junction area 150 is the second amorphized passivation portion 126.

[0086] In this way, not only the first passivation layer 111 is designed to be partially crystallized, but also the second passivation layer 112 is designed to be partially crystallized, so that the first passivation layer 111 includes a first crystallized passivation portion 115 and a first amorphized passivation portion 116, and the second passivation layer 112 includes a second crystallized passivation portion 125 and a second amorphized passivation portion 126. In other words, the crystallized passivation portion 105 includes a portion of the first passivation layer 111 and a portion of the second passivation layer 112. The crystallized passivation portion 105 is located between the first amorphized passivation portion 116 and the second amorphized passivation portion 126. The carriers collected in the first crystallized passivation portion 115 and the second crystallized passivation portion 125 can recombine to form a local leakage channel, but there will be no transverse conduction between the first amorphized passivation portion 116 and the second amorphized passivation portion 126 to ensure that a large number of carriers are eventually transmitted to the electrodes formed subsequently. This is beneficial for ensuring that the solar cell has a high photoelectric conversion efficiency. At the same time, the crystallized passivation portion 105 is designed in the first passivation layer 111 and the second passivation layer 112 to further reduce the probability of local overheating of the solar cell, which is beneficial for further improving the hot spot effect of the battery component subsequently formed based on the solar cell.

[0087] It should be noted that both the first crystallized passivation portion 115 and the second crystallized passivation portion 125 have the third crystallization rate; and both the first amorphized passivation portion 116 and the second amorphized passivation portion 126 have the fourth crystallization rate. Figure 7 In the first semiconductor doping layer 121, a first crystallized doped portion 113 is divided by a thicker dotted line, and a second crystallized doped portion 123 is divided by a thicker dotted line in the second semiconductor doping layer 122. In the first passivation layer 111, a first crystallized passivation portion 115 is divided by a thicker dotted line, and in the second passivation layer 112, a second crystallized passivation portion 125 is divided by a thicker dotted line.

[0088] also, Figure 5 In the example, only the crystallized doped portion 103 is a portion of the first semiconductor doped layer 121 and the crystallized passivation portion 105 is a portion of the first passivation layer 111 in the same boundary region 150 is taken as an example; Figure 6 In the example, only the crystallized doped portion 103 is a portion of the second semiconductor doped layer 122 and the crystallized passivation portion 105 is a portion of the second passivation layer 112 in the same boundary region 150 is taken as an example; Figure 7In the example, only the crystallized doped part 103 is a part of the first semiconductor doped layer 121 and a part of the second semiconductor doped layer 122, and the crystallized passivation part 105 is a part of the first passivation layer 111 and a part of the second passivation layer 112, on the same boundary region 150. In practical applications, on the same boundary region, the specific structure of the crystallized doped part includes the above three embodiments, and the specific structure of the crystallized passivation part includes the above three embodiments, which can be combined in any two to form 9 different embodiments. An embodiment of the present disclosure is to illustrate the 9 embodiments one by one, but those skilled in the art can flexibly select one of the 9 embodiments according to their needs.

[0089] It is worth noting that Figures 5 to 7 In the example, the same boundary region 150 is provided with both the crystallized doped portion 103 and the crystallized passivation portion 105 . In practical applications, one of the different boundary regions may have at least the crystallized doped portion and the other may have at least the crystallized passivation portion.

[0090] In the above various embodiments, reference Figures 1 to 7 The first crystallization rate of the crystallized doped portion 103 is 10% to 40%, and the second crystallization rate of the first semiconductor doping layer 121 and the second semiconductor doping layer 122 not located on the boundary region 150 is 0.

[0091] If the first crystallization rate is greater than 40%, the conductivity of the crystallized doped portion 103 is too good compared with the first semiconductor doped layer 121 and the second semiconductor doped layer 122 not located on the junction area 150, which will make the recombination probability of carriers in the crystallized doped portion 103 too large, resulting in excessive leakage at the contact between the first semiconductor doped layer 121 and the second semiconductor doped layer 122, which is not conducive to ensuring that the solar cell has a higher short-circuit current; if the first crystallization rate is less than 10%, the degree of improvement of the conductivity of the crystallized doped portion 103 is not obvious compared with the first semiconductor doped layer 121 and the second semiconductor doped layer 122 not located on the junction area 150, and the solar cell is prone to generate more heat when used as a load, which is not conducive to improving the hot spot effect of the battery assembly formed based on the subsequent solar cell. Therefore, designing the first crystallization rate to be 10% to 40% is conducive to controlling the appropriate leakage at the contact between the first semiconductor doped layer 121 and the second semiconductor doped layer 122, so as to ensure that the solar cell has a higher photoelectric conversion efficiency and improve the hot spot effect of the battery assembly formed based on the subsequent solar cell.

[0092] It is worth noting that for the first semiconductor doping layer 121 not located on the junction area 150 or the second semiconductor doping layer 122 not located on the junction area 150, the second crystallization rate can be 0. In practical applications, the second crystallization rate can also be close to 0, that is, the degree of amorphization is very high. For the first semiconductor doping layer 121 and the second semiconductor doping layer 122, the higher the crystallization rate, the higher the degree of crystallization, the closer to the polycrystalline structure, the higher the crystallization rate, the smaller the square resistance, and the better the conductive performance.

[0093] It should be noted that the first crystallization rate of the crystallized doping portion 103 refers to: the average value of the crystallization rates of each region in the crystallized doping portion 103. In other words, the first crystallization rate can reflect the average degree of crystallization of the crystallized doping portion 103. In some cases, the crystallization rates of each region in the crystallized doping portion 103 are within the range of the first crystallization rate; in other cases, the crystallization rates of most regions in the crystallized doping portion 103 are within the range of the first crystallization rate, and the crystallization rates of a small part are not within the range of the first crystallization rate, but the overall average crystallization rate of the crystallized doping portion 103 is the first crystallization rate.

[0094] In addition, the second crystallization rate of the first semiconductor doping layer 121 and the second semiconductor doping layer 122 not located on the junction area 150 refers to: the average value of the crystallization rate of each region in the first semiconductor doping layer 121 and the second semiconductor doping layer 122 not located on the junction area 150. In other words, the second crystallization rate can reflect the average degree of crystallization of the first semiconductor doping layer 121 and the second semiconductor doping layer 122 not located on the junction area 150. The distribution of the crystallization rate of each region in the first semiconductor doping layer 121 and the second semiconductor doping layer 122 not located on the junction area 150 is similar to that of the above-mentioned crystallized doping portion 103, and will not be repeated here.

[0095] In some examples, the first crystallization rate of the crystallized doped portion 103 may be 15%, 16%, 20%, 22%, 25%, 26%, 30%, 32% or 35%, etc.

[0096] In some of the above embodiments, reference Figures 5 to 7 The third crystallization rate of the crystallized passivation portion 105 can be the crystallization rate of the portion away from the substrate 100, such as the crystallization rate from the first surface 110 to the middle of the crystallized passivation portion 105 (for example, 50% of the thickness), where the crystallization rate can be 10% to 40%; the fourth crystallization rate of the first passivation layer 111 and the second passivation layer 112 not located on the junction area 150 is the same as the second crystallization rate, which is 0. In practical applications, the fourth crystallization rate of the first passivation layer 111 and the second passivation layer 112 not located on the junction area 150 can also be close to 0.

[0097] It is worth noting that for the first passivation layer 111 not located on the junction area 150 or the second passivation layer 112 not located on the junction area 150, the fourth crystallization rate can be 0 or close to 0, that is, the degree of amorphization is very high. For the first passivation layer 111 and the second passivation layer 112, the higher the crystallization rate of the region, the higher the degree of crystallization, the closer to the polycrystalline structure, the higher the crystallization rate of the region, the smaller the sheet resistance, and the better the conductive performance.

[0098] It should be noted that the third crystallization rate of the crystallization passivation part 105 refers to: the average value of the crystallization rates of each region in the crystallization passivation part 105. In other words, the third crystallization rate can reflect the average degree of crystallization of the crystallization passivation part 105. In some cases, the crystallization rates of each region in the crystallization passivation part 105 are within the range of the third crystallization rate; in other cases, the crystallization rates of most regions in the crystallization passivation part 105 are within the range of the third crystallization rate, and the crystallization rates of a small part are not within the range of the third crystallization rate, but the overall average crystallization rate of the crystallization passivation part 105 is the third crystallization rate.

[0099] In addition, the fourth crystallization rate of the first passivation layer 111 and the second passivation layer 112 not located on the junction area 150 refers to: the average value of the crystallization rate of each region in the first passivation layer 111 and the second passivation layer 112 not located on the junction area 150. In other words, the fourth crystallization rate can reflect the average crystallization degree of the first passivation layer 111 and the second passivation layer 112 not located on the junction area 150. The distribution of the crystallization rate of each region in the first passivation layer 111 and the second passivation layer 112 not located on the junction area 150 is similar to that of the above-mentioned crystallized passivation portion 105, and will not be repeated here.

[0100] In the above various embodiments, reference Figures 1 to 7 , the grain size in the crystallized doped portion 103 may be 5nm to 30nm. Different from this, the first semiconductor doping layer 121 and the second semiconductor doping layer 122 not located on the boundary region 150 may not have grains, or may have extremely small grains, for example, grains with a size less than 5nm. It should be noted that the grain size refers to the diameter of the grains.

[0101] If the grain size in the crystallized doped portion 103 is greater than 30 nm, compared with the first semiconductor doping layer 121 and the second semiconductor doping layer 122 not located on the junction area 150, the excessively large grain size of the crystallized doped portion 103 will make the transmission probability of carriers in the crystallized doped portion 103 too large, resulting in excessive leakage at the contact point between the first semiconductor doping layer 121 and the second semiconductor doping layer 122, which is not conducive to ensuring that the solar cell has a high photoelectric conversion efficiency; if the grain size in the crystallized doped portion 103 is less than 5 nm, compared with the first semiconductor doping layer 121 and the second semiconductor doping layer 122 not located on the junction area 150, the degree of improvement in the conductivity of the crystallized doped portion 103 is not obvious, and the solar cell is prone to generate more heat when used as a load, which is not conducive to improving the hot spot effect of the battery component formed based on the solar cell later. Therefore, designing the grain size in the crystallized doping part 103 to be 5nm to 30nm is beneficial to controlling the leakage level at the contact between the first semiconductor doping layer 121 and the second semiconductor doping layer 122 to be appropriate, so as to ensure that the solar cell has a high photoelectric conversion efficiency and improve the hot spot effect of the battery component formed subsequently based on the solar cell.

[0102] In some examples, the grain size in the crystallized doped portion 103 may be 8 nm, 10 nm, 12 nm, 15 nm, 18 nm, 20 nm, 24 nm, 25 nm, or 28 nm, etc.

[0103] In some embodiments, reference Figure 4 The crystallized doping portion 103 includes a first crystallized doping portion 113 and a second crystallized doping portion 123 . The grain size in the first crystallized doping portion 113 and the grain size in the second crystallized doping portion 123 may both be 5 nm to 30 nm.

[0104] In some of the above embodiments, reference Figures 5 to 7 The grain size in the crystallized passivation part 105 is the same as the grain size in the crystallized doping part 103, and both can be 5nm to 30nm. In some examples, the grain size in the crystallized passivation part 105 can be 8nm, 10nm, 12nm, 15nm, 18nm, 20nm, 24nm, 25nm or 28nm.

[0105] In some embodiments, reference Figure 7 The crystallized passivation portion 105 includes the first crystallized passivation portion 115 or the second crystallized passivation portion 125 , and the grain size in the first crystallized passivation portion 115 or the second crystallized passivation portion 125 can be 5 nm to 30 nm.

[0106] In the above various embodiments, reference Figures 1 to 7 The ratio of the area of ​​the boundary region 150 to the area of ​​the first region 130 may be 1% to 30%.

[0107] If the ratio of the area of ​​the junction region 150 to the area of ​​the first region 130 is greater than 30%, the area occupied by the crystallized doped portion 103 in the semiconductor doped layer is too large compared to the first semiconductor doped layer 121 and the second semiconductor doped layer 122 not located on the junction region 150, so that the proportion of the crystallized portion in the semiconductor doped layer is too large, which may also easily lead to excessive leakage at the contact between the first semiconductor doped layer 121 and the second semiconductor doped layer 122, which is not conducive to ensuring that the solar cell has a high photoelectric conversion efficiency. In addition, the electrode in the solar cell and the semiconductor doped layer not located on the junction region 150 are not connected. The area of ​​the crystallized doped portion 103 in the semiconductor doping layer is too large, which will also limit the area of ​​electrical contact between the electrode and the semiconductor doping layer not located on the junction area 150; if the ratio of the area of ​​the junction area 150 to the area of ​​the first area 130 is less than 1%, the area of ​​the crystallized doped portion 103 in the semiconductor doping layer is too small, so that the proportion of the crystallized part in the semiconductor doping layer is too small, which is not conducive to improving the overall conductivity of the crystallized doped portion 103. When the solar cell is used as a load, it is easy to generate more heat, which is not conducive to improving the hot spot effect of the battery component formed based on the solar cell later.

[0108] Therefore, the ratio of the area of ​​the interface region 150 to the area of ​​the first region 130 can be designed to be 1% to 30%, which is conducive to controlling the proportion of the crystallized part in the semiconductor doping layer to be moderate, that is, controlling the volume of the crystallized doping part 103 to be moderate, thereby helping to control the leakage degree at the contact between the first semiconductor doping layer 121 and the second semiconductor doping layer 122 to be appropriate, so as to ensure that the solar cell has a high photoelectric conversion efficiency and improve the hot spot effect of the battery assembly formed based on the solar cell later. It should be noted that the semiconductor doping layer described above includes at least one of the first semiconductor doping layer 121 and the second semiconductor doping layer 122.

[0109] In some examples, the ratio of the area of ​​the interface region 150 to the area of ​​the first region 130 may be 2%, 5%, 8%, 10%, 15%, 18%, 20%, 24%, 25%, 28%, etc.

[0110] In some embodiments, in addition to the crystallized doping part 103, the junction area 150 also has a crystallized passivation part 105. The ratio of the area of ​​the junction area 150 to the area of ​​the first area 130 is 1% to 30%, which is also conducive to controlling the proportion of the crystallized part in the passivation layer to be moderate, that is, controlling the volume of the crystallized passivation part 105 to be moderate, so as to control the leakage degree of the contact between the first passivation layer 111 and the second passivation layer 112 to be appropriate, so as to ensure that the solar cell has a high photoelectric conversion efficiency and further improve the hot spot effect of the battery assembly formed based on the solar cell. It should be noted that the passivation layer described in this paragraph includes at least one of the first passivation layer 111 and the second passivation layer 112.

[0111] In some embodiments, the ratio of the area of ​​the first region 130 to the area of ​​the second region 140 may be close to 1.

[0112] In some cases, in the above various embodiments, reference Figures 1 to 4 , if the boundary region 150 has only the crystallized doped portion 103 but no crystallized passivation portion, the materials of the first passivation layer 111 and the second passivation layer 112 may be at least one of amorphous silicon or silicon oxide; in other cases, refer to Figures 5 to 7 If the junction area 150 has a crystallized doped portion 103 and a crystallized passivation portion 105, the materials of the first passivation layer 111 not located on the junction area 150 and the second passivation layer 112 not located on the junction area 150 can be at least one of amorphous silicon or silicon oxide, and the material of the crystallized passivation portion 105 can be at least one of amorphous silicon or silicon oxide after crystallization. Among them, the amorphous silicon after crystallization can be regarded as polycrystalline silicon.

[0113] In one example, the amorphous silicon may be intrinsic hydrogenated amorphous silicon (abbreviated as a-Si:H(i), or ia-Si:H), and the silicon oxide may be intrinsic hydrogenated amorphous silicon oxide (abbreviated as a-SiO x :H(i), or ia-SiO x :H).

[0114] In the above-mentioned various embodiments, the material of one of the first semiconductor doping layer 121 not located on the junction area 150 and the second semiconductor doping layer 122 not located on the junction area 150 can be n-type amorphous silicon, n-type amorphous silicon carbide (abbreviated as a-SiC x (n), or na-SiC x ) or n-type amorphous silicon oxide (abbreviated as a-SiO x (n), or na-SiO x ), and the material of the other one can be p-type amorphous silicon, p-type amorphous silicon carbide (abbreviated as a-SiC x (p), or pa-SiCx ) or p-type amorphous silicon oxide (abbreviated as a-SiO x (p), or pa-SiO x ). The material of the crystallized doped portion 103 may be at least one of n-type amorphous silicon, n-type amorphous silicon carbide, n-type amorphous silicon oxide, p-type amorphous silicon, p-type amorphous silicon carbide or p-type amorphous silicon oxide after crystallization. Among them, the n-type amorphous silicon after crystallization can be regarded as n-type polycrystalline silicon, and the p-type amorphous silicon after crystallization can be regarded as p-type polycrystalline silicon.

[0115] In one example, the n-type amorphous silicon may be n-type hydrogenated amorphous silicon (abbreviated as a-Si:H(n), or na-Si:H), and the p-type amorphous silicon may be p-type hydrogenated amorphous silicon (abbreviated as a-Si:H(p), or pa-Si:H).

[0116] In an example, the materials of the first passivation layer 111 and the second passivation layer 112 are both intrinsic amorphous silicon, the materials of the first semiconductor doping layer 121 not located on the junction area 150 and the second semiconductor doping layer 122 not located on the junction area 150 are both doped amorphous silicon (i.e., n-type amorphous silicon or p-type amorphous silicon), the first passivation layer 111 and the first semiconductor doping layer 121 form a heterojunction passivation contact structure, and the second passivation layer 112 and the second semiconductor doping layer 122 form a heterojunction passivation contact structure, and the solar cell is an HBC cell (Heterojunction-Interdigitated Back Contact Cell).

[0117] In another example, the materials of the first passivation layer 111 and the second passivation layer 112 are both silicon oxide, the materials of the first semiconductor doping layer 121 not located on the junction area 150 and the second semiconductor doping layer 122 not located on the junction area 150 can both be semiconductor materials with doped elements, the first passivation layer 111 and the first semiconductor doping layer 121 form a tunneling passivation contact structure, and the second passivation layer 112 and the second semiconductor doping layer 122 form a tunneling passivation contact structure, and the solar cell is a TBC cell (TOPCon-BC Cell, back junction back contact cell).

[0118] The solar cell provided in one embodiment of the present disclosure is described in detail below by taking as an example that the materials of the first passivation layer 111 and the second passivation layer 112 are both a-Si:H(i), the first semiconductor doping layer 121 not located on the junction area 150 is na-Si:H, the material of the second semiconductor doping layer 122 not located on the junction area 150 is pa-Si:H, and the crystallized doping part 103 is doped polycrystalline silicon (i.e., n-type polycrystalline silicon and / or p-type polycrystalline silicon).

[0119] Compared with conventional heterojunction technology, in order to reduce the parasitic absorption of silicon film and improve the contact resistance between silicon film and transparent conductive oxide (TCO), doped amorphous silicon film, such as na-Si:H or pa-Si:H, is usually prepared into doped microcrystalline or nanocrystalline silicon film, such as n-nc-Si:H or p-nc-Si:H in double-sided heterojunction cells. Since microcrystalline or nanocrystalline silicon film has small square resistance and strong lateral conductivity, when doped microcrystalline or nanocrystalline silicon film is used in back contact technology, it is easy to cause serious leakage of the battery at the junction of n-region and p-region, affecting the efficiency of the battery. Based on this, in the solar cell provided in an embodiment of the present disclosure, the first semiconductor doping layer 121 not located on the junction area 150 is designed to be na-Si:H, the material of the second semiconductor doping layer 122 not located on the junction area 150 is pa-Si:H, and the crystallized doping part 103 is doped polycrystalline silicon (i.e., n-type polycrystalline silicon and / or p-type polycrystalline silicon), which is beneficial for making the first semiconductor doping layer 121 and the second semiconductor doping layer 122 have a small amount of leakage at the junction along the first direction X with the help of the crystallized doping part 103, and there is no conduction between the entire first semiconductor doping layer 121 and the entire second semiconductor doping layer 122, thereby avoiding leakage between the first semiconductor doping layer 121 not located on the junction area 150 and the second semiconductor doping layer 122 not located on the junction area 150. In this way, on the one hand, the probability of carrier recombination in the crystallized doped part 103 is used to reduce the probability of local overheating when the solar cell is used as a load; on the other hand, based on the non-conduction between the entire first semiconductor doped layer 121 and the entire second semiconductor doped layer 122, it is ensured that the solar cell has a high photoelectric conversion efficiency. In addition, compared with the low deposition rate and high cost when the crystallized silicon thin film is formed by depositing the entire surface, in one embodiment of the present disclosure, the crystallized doped part 103 is formed only in a part of the first semiconductor doped layer 121 and / or a part of the entire second semiconductor doped layer 122, which is beneficial to reduce the preparation cost of the first semiconductor doped layer 121, the second semiconductor doped layer 122 and the crystallized doped part 103 and improve the preparation efficiency of the solar cell.

[0120] In some embodiments, reference Figure 8 , Figure 8 This is a schematic diagram of an eighth partial cross-sectional structure of a solar cell provided in an embodiment of the present disclosure. The solar cell may further include: a third passivation layer 139 and an anti-reflection layer 149 stacked along the second direction Y on the second surface 120 .

[0121] In summary, the crystallized doped portion 103 is designed at least between the first semiconductor doped layer 121 not located on the junction area 150 and the second semiconductor doped layer 122 not located on the junction area 150. Compared with the first semiconductor doped layer 121 not located on the junction area 150 and the second semiconductor doped layer 122 not located on the junction area 150, the first crystallization rate of the crystallized doped portion 103 is higher, and the crystallized doped portion 103 has a smaller square resistance and stronger lateral conductivity. In this way, at least one of the first semiconductor doped layer 121 and the second semiconductor doped layer 122 is partially designed to have strong lateral conductivity, which is conducive to reducing the probability of local overheating when the solar cell is used as a load by means of the local leakage channel formed based on the crystallized doped portion 103, so as to improve the hot spot effect caused by local shading or defects in the battery component formed based on the solar cell, so as to improve the structural stability of the photovoltaic component.

[0122] Another embodiment of the present disclosure further provides a method for preparing a solar cell, which is used to prepare the solar cell provided by the above embodiment. The method for preparing a solar cell provided by another embodiment of the present disclosure will be described in detail below in conjunction with the accompanying drawings. Figures 9 to 16 This is a schematic diagram of a partial cross-sectional structure corresponding to each step in a method for preparing a solar cell provided in another embodiment of the present disclosure. It should be noted that parts that are the same as or corresponding to the aforementioned embodiments are not described in detail herein.

[0123] Combined with reference Figures 1 to 8 ,as well as Figures 9 to 16 , the preparation method of the solar cell comprises the following steps:

[0124] S1: providing a substrate 100 , wherein the substrate 100 has a first surface 110 and a second surface 120 opposite to each other, wherein the first surface 110 includes first regions 130 and second regions 140 alternately arranged along a first direction X.

[0125] S2: An initial first passivation structure 131 and an initial second passivation structure 132 are sequentially formed on the first surface 110, wherein the initial first passivation structure 131 is located on the first region 130, and the initial first passivation structure 131 includes an initial first passivation layer 141 and an initial first semiconductor doping layer 151 stacked along the second direction Y, and the initial second passivation structure 132 is at least located on the second region 140, and the initial second passivation structure 132 includes an initial second passivation layer 142 and an initial second semiconductor doping layer 152 stacked along the second direction Y, and the doping type of the initial first semiconductor doping layer 151 is different from the doping type of the initial second semiconductor doping layer 152; wherein the first surface 110 also includes a junction area 150, and the junction area 150 includes a portion of at least one of the first region 130 and the second region 140, and the sidewalls of the initial first semiconductor doping layer 151 and the sidewalls of the initial second semiconductor doping layer 152 are in contact with each other on the junction area 150.

[0126] S3: Performing laser crystallization treatment on a portion of at least one of the initial first semiconductor doping layer 151 and the initial second semiconductor doping layer 152 located on the junction area 150 to transform the initial first passivation structure 131 into the first passivation structure 101, transform the initial second passivation structure 132 into the second passivation structure 102, and form a crystallized doping portion 103 on at least a portion of the junction area 150.

[0127] It is worth noting that the crystallized doped portion 103 is formed by laser crystallization based on a portion of the initial first semiconductor doped layer 151 and / or a portion of the initial second semiconductor doped layer 152, so that the crystallization rate of the crystallized doped portion 103 is higher than the crystallization rate of the initial first semiconductor doped layer 151 and the initial second semiconductor doped layer 152 not located on the junction area 150. In other words, step S3 enables the crystallized doped portion 103 to have a first crystallization rate, and the initial first semiconductor doped layer 151 and the initial second semiconductor doped layer 152 not located on the junction area 150 to have a second crystallization rate, and the first crystallization rate is greater than the second crystallization rate, so that while ensuring that the solar cell has a high photoelectric conversion efficiency, the probability of local overheating of the solar cell is reduced by means of the crystallized doped portion 103, so as to improve the hot spot effect of the battery component formed based on the solar cell later. The initial first semiconductor doping layer 151 not located on the junction area 150 is not laser crystallized and serves as the first semiconductor doping layer 121 , and the initial second semiconductor doping layer 152 not located on the junction area 150 is not laser crystallized and serves as the second semiconductor doping layer 122 .

[0128] The following is a detailed description of each step of the method for preparing a photovoltaic cell:

[0129] In some embodiments, reference Fig. 9In step S1, the step of improving the substrate 100 may include the following steps: polishing the first surface 110 of the substrate 100 so that the surface of the first area 130 and the surface of the second area 140 are both polished surfaces; and texturing the second surface 120 of the substrate 100 so that the second surface 120 has a suede structure. It should be noted that the step of texturing the second surface 120 of the substrate 100 may be performed before or after forming the first passivation structure 101 and the second passivation structure 102.

[0130] In some examples, the material of the substrate 100 may include at least one of single crystal silicon, germanium, or gallium arsenide. In some examples, the doping type of the substrate 100 may be N-type doping or P-type doping.

[0131] In some embodiments, forming the first passivation structure 101 and the second passivation structure 102 in step S2 may include the following steps:

[0132] refer to Fig.10 A first passivation stack 161 is formed on the first surface 110 , and the first passivation stack 161 includes an initial first passivation layer 141 and an initial first semiconductor doping layer 151 stacked along the second direction Y.

[0133] In some examples, the initial first passivation layer 141 and the initial first semiconductor doping layer 151 may be prepared by plasma enhanced chemical vapor deposition (PECVD) or hot wire chemical vapor deposition (HWCVD).

[0134] In some examples, the material of the initial first passivation layer 141 may be amorphous silicon or silicon oxide, and the thickness of the initial first passivation layer 141 ranges from 1 nm to 20 nm, for example, 2 nm, 4 nm, 5 nm, 7 nm, 10 nm, 12 nm, 15 nm, 16 nm or 18 nm. It is worth noting that, compared with PECVD, when HWCVD is used to deposit the hydrogenated amorphous silicon film to form the initial first passivation layer 141, it is based on the thermal decomposition of the reaction gas by the hot wire, and there is no plasma bombardment of the substrate 100, which is conducive to the formation of a high-quality hydrogenated amorphous silicon film, and an interface with a significant mutation is formed between the initial first passivation layer 141 and the first surface 110, which is conducive to further improving the passivation effect of the first passivation layer formed based on the initial first passivation layer 141 on the substrate. In addition, no matter what kind of film layer is formed based on HWCVD deposition, the bombardment of the existing film layer by plasma can be avoided.

[0135] In some examples, the material of the initial first semiconductor doping layer 151 can be n-type amorphous silicon, n-type amorphous silicon carbide or n-type amorphous silicon oxide, and the thickness of the initial first semiconductor doping layer 151 ranges from 2nm to 50nm, for example, 5nm, 15nm, 20nm, 25nm, 30nm, 35nm, 40nm or 45nm, etc.

[0136] In some cases, after forming the first passivation stack 161 and before forming the second passivation stack, the preparation method may further include: forming an initial insulating layer 119 and a laser absorption layer 129 in sequence on a side of the first passivation stack 161 away from the substrate 100 along the second direction Y. The initial insulating layer 119 has good moisture and heat resistance and can isolate water vapor to protect the first passivation stack 161, and can separate the first passivation stack 161 and the second passivation stack formed subsequently along the second direction Y; in the subsequent laser film opening process, the laser absorption layer 129 can absorb excess laser light, protect the first passivation stack 161 between the laser absorption layer 129 and the substrate 100, avoid thermal attenuation of the first passivation stack 161, and improve the open circuit voltage and photoelectric conversion efficiency of the solar cell finally formed.

[0137] In some examples, the material of the initial insulating layer 119 can be at least one of silicon nitride or silicon oxide, and the thickness of the initial insulating layer 119 ranges from 10nm to 200nm, for example, 20nm, 40nm, 50nm, 60nm, 80nm, 100nm, 120nm, 150nm, 160nm or 180nm, etc.

[0138] In some examples, the material of the laser absorption layer 129 can be a laser absorption material, and the thickness of the initial insulating layer 119 ranges from 10nm to 200nm, for example, 20nm, 40nm, 50nm, 60nm, 80nm, 100nm, 120nm, 150nm, 160nm or 180nm.

[0139] Combined with reference Figures 11 to 14 , a first patterning process is performed on the first passivation stack 161 to expose the second region 140 , and the remaining first passivation stack 161 is the first passivation structure 101 .

[0140] In some cases, reference Fig.11 The first passivation stack 161 is further formed with an initial insulating layer 119 and a laser absorption layer 129 on the side away from the substrate 100; the first patterning step may include: combining reference Fig.11 and Fig.12 , using laser to remove the laser absorption layer 129 located on the second region 140, thereby forming a first opening 10 exposing the initial insulating layer 119; combined with reference Fig.12 and Fig.13 , using a first wet process, removing the initial insulating layer 119 exposed by the first opening 10, and removing the first passivation stack 161 located on the second region 140 to expose the second region 140, and the remaining first passivation stack 161 is used as the initial first passivation structure 131; continue to combine with reference Fig.12 and Fig.13 , a second wet process is used to remove the remaining laser absorption layer 129 to expose the initial insulation layer 119 on the first region 130 .

[0141] It should be noted that the process parameters used in the first wet process and the second wet process are different, for example, the etching solutions used are different. In one example, the etching solution used in the first wet process may be an alkaline polishing solution, and while removing the first passivation stack 161 located on the second area 140, the second area 140 is polished to form a polished surface in the second area 140 to reduce surface defects in the second area 140; the etching solution used in the second wet process may be hydrofluoric acid.

[0142] In other cases, combined with reference Fig.10 and Fig.14 The first patterning step may include: directly using a laser selective etching process to remove the first passivation stack 161 located on the second region 140 to expose the second region 140 , and the remaining first passivation stack 161 serves as an initial first passivation structure 131 .

[0143] Combined with reference Fig.13 and Fig.15 , forming a second passivation stack 162, the second passivation stack 162 is located on the side of the initial first passivation structure 131 away from the first area 130 and on the exposed second area 140, the second passivation stack 162 includes an initial second passivation layer 142 and an initial second semiconductor doping layer 152 stacked along the second direction Y, and the doping type of the initial first semiconductor doping layer 151 is different from the doping type of the initial second semiconductor doping layer 152.

[0144] In some examples, the initial second passivation layer 142 and the initial second semiconductor doping layer 152 can be prepared by plasma enhanced chemical vapor deposition (PECVD) or hot wire chemical vapor deposition (HWCVD). It should be noted that the same or corresponding parts as those of the above-mentioned preparation of the initial first passivation layer 141 and the initial first semiconductor doping layer 151 are not repeated here.

[0145] In some examples, the material of the initial second passivation layer 142 may be amorphous silicon or silicon oxide, and the thickness of the initial first passivation layer 141 may range from 1 nm to 20 nm, for example, 2 nm, 4 nm, 5 nm, 7 nm, 10 nm, 12 nm, 15 nm, 16 nm or 18 nm, etc. In one example, the material of the initial first passivation layer 141 and the material of the initial second passivation layer 142 may both be a-Si:H(i) or a-SiOx:H(i).

[0146] In some examples, the material of the initial second semiconductor doping layer 152 can be p-type amorphous silicon, p-type amorphous silicon carbide or p-type amorphous silicon oxide, and the thickness of the initial second semiconductor doping layer 152 ranges from 2nm to 50nm, for example, 5nm, 15nm, 20nm, 25nm, 30nm, 35nm, 40nm or 45nm, etc.

[0147] It should be noted that in another embodiment of the present disclosure, the preparation method provided is described by taking the doping type of the initial first semiconductor doping layer 151 as n-type and the doping type of the initial second semiconductor doping layer 152 as p-type as an example. In practical applications, the doping type of the initial first semiconductor doping layer may be p-type, and the doping type of the initial second semiconductor doping layer may be n-type.

[0148] Combined with reference Fig.15 and Fig.16 , a second patterning process is performed on the second passivation stack 162 to expose at least a portion of the initial first passivation structure 131 , and the remaining second passivation stack 162 is the initial second passivation structure 132 .

[0149] In some cases, the second graphical processing step may include: combining the reference Fig.15 and Fig.16 , using laser to remove at least a portion of the second passivation stack 162 located on the first region 130, thereby forming a second opening 20 exposing at least a portion of the initial insulating layer 119; continue to combine with reference Fig.15 and Fig.16 , using a third wet process to remove the initial insulating layer 119 exposed by the second opening 20 to expose at least a portion of the initial first passivation structure 131 , the remaining initial insulating layer 119 serves as the insulating layer 109 , and the remaining second passivation stack 162 serves as the initial second passivation structure 132 .

[0150] It should be noted that the process parameters used in the third wet process and the first wet process may be the same.

[0151] In other cases, combined with reference Fig.15 and Fig.16The second patterning step may include: directly using a laser selective etching process to remove at least a portion of the second passivation stack 162 located on the first region 130 to expose at least a portion of the initial first passivation structure 131 , and the remaining second passivation stack 162 serves as the initial second passivation structure 132 .

[0152] It should be noted that Fig.16 In the example, only a portion of the second passivation stack 162 located on the first region 130 is removed, a portion of the initial second passivation structure 132 is still located on the first region 130, and an insulating layer 109 is further provided between the initial second passivation structure 132 and the initial first passivation structure 131. In practical applications, the second passivation stack located on the first region may be completely removed, and the insulating layer located on the first region may also be completely removed.

[0153] The formation of the first passivation structure 101 , the second passivation structure 102 and the crystallized doped portion 103 in step S3 is described in detail below.

[0154] In some embodiments, in conjunction with reference Fig.16 and Figure 2 , the junction area 150 is part of the first area 130, and the laser crystallization step in step S3 may include: performing laser crystallization treatment on the initial first semiconductor doping layer 151 located on the junction area 150 to transform the initial first semiconductor doping layer 151 located on the junction area 150 into a crystallized doping portion 103, and the remaining initial first semiconductor doping layer 151 serves as the first semiconductor doping layer 121, and the initial second semiconductor doping layer 152 formed in step S2 is the second semiconductor doping layer 122.

[0155] In other embodiments, in combination with reference Fig.16 and Figure 3 , the junction area 150 is part of the second area 140, and the laser crystallization step in step S3 may include: performing laser crystallization treatment on the initial second semiconductor doping layer 152 located on the junction area 150 to transform the initial second semiconductor doping layer 152 located on the junction area 150 into a crystallized doping portion 103, and the remaining initial second semiconductor doping layer 152 serves as the second semiconductor doping layer 122, and the initial first semiconductor doping layer 151 formed in step S2 is the first semiconductor doping layer 121.

[0156] In some other embodiments, in combination with reference Fig.16 and Figure 4, the junction area 150 includes a portion of the first area 130 and a portion of the second area 140, and the step of laser crystallization treatment in step S3 may include: the initial first semiconductor doping layer 151 and the initial second semiconductor doping layer 152 located on the junction area 150 are both subjected to laser crystallization treatment to transform the initial first semiconductor doping layer 151 located on the junction area 150 into a first crystallized doping portion 113, and transform the initial second semiconductor doping layer 152 located on the junction area 150 into a second crystallized doping portion 123, the remaining initial first semiconductor doping layer 151 serves as the first semiconductor doping layer 121, and the remaining initial second semiconductor doping layer 152 serves as the second semiconductor doping layer 122, and the crystallized doping portion 103 includes a first crystallized doping portion 113 and a second crystallized doping portion 123.

[0157] In some embodiments, based on the above three embodiments of forming the crystallized doped portion 103, the laser crystallization step in step S3 may further include: Fig.16 and Figures 5 to 7 A laser crystallization process is performed on a portion of at least one of the initial first passivation layer 141 and the initial second passivation layer 142 located on the boundary region 150 to form a crystallized passivation portion 105 on at least a portion of the boundary region 150 .

[0158] The formation of the crystallization passivation portion 105 in step S3 is described in detail below.

[0159] In some embodiments, in conjunction with reference Fig.16 and Figure 5 , the junction area 150 is part of the first area 130, and the laser crystallization step in step S3 may also include: performing laser crystallization treatment on the initial first passivation layer 141 located on the junction area 150 to transform the initial first passivation layer 141 located on the junction area 150 into a crystallized passivation portion 105, and the remaining initial first passivation layer 141 serves as the first passivation layer 111, and the initial second passivation layer 142 formed in step S2 is the second passivation layer 112.

[0160] In other embodiments, in combination with reference Fig.16 and Figure 6 , the junction area 150 is part of the second area 140, and the laser crystallization step in step S3 may include: performing laser crystallization treatment on the initial second passivation layer 142 located on the junction area 150 to transform the initial second passivation layer 142 located on the junction area 150 into a crystallized passivation portion 105, and the remaining initial second passivation layer 142 serves as the second passivation layer 112, and the initial first passivation layer 141 formed in step S2 is the first passivation layer 111.

[0161] In some other embodiments, in combination with reference Fig.16 and Figure 7 , the junction area 150 includes a portion of the first area 130 and a portion of the second area 140, and the step of laser crystallization treatment in step S3 may include: performing laser crystallization treatment on the initial first passivation layer 141 and the initial second passivation layer 142 located on the junction area 150 to transform the initial first passivation layer 141 located on the junction area 150 into a first crystallized passivation portion 115, and transform the initial second passivation layer 142 located on the junction area 150 into a second crystallized passivation portion 125, the remaining initial first passivation layer 141 serves as the first passivation layer 111, and the remaining initial second passivation layer 142 serves as the second passivation layer 112, and the crystallized passivation portion 105 includes a first crystallized passivation portion 115 and a second crystallized passivation portion 125.

[0162] In some cases, the crystallized doping portion 103 and the crystallized passivation portion 105 on the same junction region 150 can be formed by the same laser crystallization process. For example, the laser in the laser crystallization process can use red light with a wavelength range of 800nm ​​to 1600nm, so that the laser can pass through the insulating layer 109 to perform laser crystallization on the initial first passivation structure 131 and / or the initial second passivation structure 132 located on the junction region 150.

[0163] It should be noted that, in practical applications, the first laser crystallization process can be performed when the initial first passivation structure is formed, and the second laser crystallization process is performed after the initial second passivation structure is subsequently formed to form a crystallized doped portion and a crystallized passivated portion on the same boundary region. In other words, the crystallized doped portion and the crystallized passivated portion can be formed separately through different steps according to different requirements.

[0164] In addition, in practical applications, at least a crystallized doped portion may be formed on one of the different boundary regions, and at least a crystallized passivation portion may be formed on the other. In other words, the steps of forming the crystallized doped portion and forming the crystallized passivation portion may be flexibly adjusted according to requirements.

[0165] In some embodiments, after forming step S3, the preparation method may further include: referring to Figures 2 to 7 , forming a conductive layer 107, the conductive layer 107 is located at least on a portion of the surface of the first passivation structure 101 away from the first surface 110, and at least on a portion of the surface of the second passivation structure 102 away from the first surface 110; forming a first electrode 118 and a second electrode 128, the first electrode 118 is located on a side of the conductive layer 107 on the first region 130 away from the first passivation structure 101, and the second electrode 128 is located on a side of the conductive layer 107 on the second region 140 away from the second passivation structure 102.

[0166] In some examples, the conductive layer 107 may be a transparent conductive film, and the thickness of the conductive layer 107 may range from 30 nm to 100 nm, for example, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 75 nm, 80 nm, 85 nm, 90 nm or 95 nm.

[0167] In some embodiments, after performing step S2 and before performing step S3, the preparation method may further include: referring to Figure 8 , a third passivation layer 139 and an anti-reflection layer 149 are sequentially formed on the second surface 120. It should be noted that, in practical applications, the steps of forming the third passivation layer and the anti-reflection layer can be performed before step S2 or after step S3. In other words, the steps of forming the third passivation layer and the anti-reflection layer can be flexibly adjusted according to actual conditions.

[0168] In some examples, the third passivation layer 139 and the anti-reflection layer 149 are sequentially deposited on the second surface 120 by PECVD or HWCVD.

[0169] In some examples, the material of the third passivation layer 139 may be at least one of amorphous silicon or aluminum oxide, and the thickness of the third passivation layer 139 may range from 1 nm to 20 nm, for example, 2 nm, 4 nm, 5 nm, 7 nm, 10 nm, 12 nm, 15 nm, 16 nm or 18 nm, etc.

[0170] In some examples, the material of the anti-reflection layer 149 may be at least one of silicon nitride, silicon oxide, silicon oxynitride or magnesium fluoride, and the thickness of the anti-reflection layer 149 may be in the range of 30nm to 200nm, for example, 50nm, 80nm, 100nm, 120nm, 150nm, 160nm or 180nm, etc.

[0171] In summary, laser crystallization of a portion of at least one of the initial first semiconductor doping layer 151 and the initial second semiconductor doping layer 152 located on the boundary region 150 is beneficial for partially designing at least one of the subsequently formed first semiconductor doping layer 121 and the second semiconductor doping layer 122 to have stronger lateral conductivity, thereby facilitating, by means of a local leakage current channel formed based on the crystallized doping portion 103, reducing the probability of local overheating when the solar cell is used as a load, thereby improving the hot spot effect caused by local shading or defects in the battery assembly formed based on the solar cell, and improving the structural stability of the photovoltaic assembly.

[0172] Another embodiment of the present disclosure further provides a photovoltaic module, which is used to convert received light energy into electrical energy. The photovoltaic module provided by another embodiment of the present disclosure will be described in detail below in conjunction with the accompanying drawings. It should be noted that the parts that are the same or corresponding to the above embodiments are not repeated here.

[0173] Fig.17 A schematic diagram of a partial three-dimensional structure of a photovoltaic assembly provided in yet another embodiment of the present disclosure. Fig.18 for Fig.17 Schematic diagram of a cross-sectional structure along section A-A2.

[0174] refer to Fig.17 and Fig.18 The photovoltaic module includes: a battery string, which is formed by connecting a plurality of solar cells 40 provided in the above-mentioned embodiments, or by connecting a plurality of solar cells 40 formed by the preparation method provided in the above-mentioned embodiments; a packaging film 41, which is used to cover the surface of the battery string; and a cover plate 42, which is used to cover the surface of the packaging film 41 away from the battery string.

[0175] In some embodiments, in conjunction with reference Figure 2 and Fig.17 , multiple first welding strips 43 and multiple second welding strips 44 are arranged at intervals along the first direction X, the first welding strips 43 and the second welding strips 44 are parallel to each other and arranged alternately, the first electrodes 118 in two adjacent solar cells 40 are electrically connected through the first welding strips 43, and the second electrodes 128 in two adjacent solar cells 40 are electrically connected through the second welding strips 44.

[0176] In some embodiments, no intervals are set between the solar cells 40 , that is, the solar cells 40 overlap with each other.

[0177] In some embodiments, reference Fig.18 The encapsulation film 41 includes a first encapsulation layer and a second encapsulation layer, the first encapsulation layer covers one of the front side or the back side of the photovoltaic cell 40, and the second encapsulation layer covers the other of the front side or the back side of the photovoltaic cell 40. Specifically, at least one of the first encapsulation layer or the second encapsulation layer can be an organic encapsulation film such as a polyvinyl butyral (PVB) film, an ethylene-vinyl acetate copolymer (EVA) film, a polyethylene octene co-elastomer (POE) film or a polyethylene terephthalate (PET) film.

[0178] In some cases, there is a boundary between the first encapsulation layer and the second encapsulation layer before lamination. After the lamination process, the photovoltaic module is formed and there is no longer the concept of the first encapsulation layer and the second encapsulation layer, that is, the first encapsulation layer and the second encapsulation layer have formed an integral encapsulation film 41.

[0179] In some embodiments, reference Fig.18 The cover plate 42 may be a glass cover plate, a plastic cover plate or the like with a light-transmitting function. Specifically, the surface of the cover plate 42 facing the encapsulation film 41 may be a concave-convex surface, thereby increasing the utilization rate of the incident light. The cover plate 42 includes a first cover plate and a second cover plate, the first cover plate is opposite to the first encapsulation layer, and the second cover plate is opposite to the second encapsulation layer.

[0180] Those skilled in the art can understand that the above-mentioned embodiments are specific examples for implementing the present disclosure, and in practical applications, various changes can be made to them in form and detail without departing from the spirit and scope of the embodiments of the present disclosure. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the embodiments of the present disclosure, so the protection scope of the embodiments of the present disclosure shall be based on the scope defined in the claims.

Claims

1. A solar cell, characterized in that: include: A substrate having a first surface and a second surface opposite to each other, wherein the first surface includes first areas and second areas alternately arranged along a first direction; A first passivation structure, located on the first region, the first passivation structure comprising a first passivation layer and a first semiconductor doping layer stacked along a second direction; a second passivation structure, at least located on the second region, the second passivation structure comprising a second passivation layer and a second semiconductor doping layer stacked along the second direction, the doping type of the first semiconductor doping layer and the doping type of the second semiconductor doping layer being different; The first surface also includes a junction area, the junction area includes a portion of at least one of the first area and the second area, and the side wall of the first semiconductor doping layer and the side wall of the second semiconductor doping layer are in contact with each other on the junction area, wherein at least a portion of the junction area has a crystallized doping portion, the crystallized doping portion is a portion of at least one of the first semiconductor doping layer and the second semiconductor doping layer, the crystallized doping portion has a first crystallization rate, the first semiconductor doping layer and the second semiconductor doping layer not located on the junction area have a second crystallization rate, and the first crystallization rate is greater than the second crystallization rate.

2. The solar cell according to claim 1, characterized in that The junction area is part of the first region, the crystallized doped portion is a portion of the first semiconductor doped layer located on the junction area, and a portion of the first semiconductor doped layer not located on the junction area is an amorphized doped portion.

3. The solar cell according to claim 1, characterized in that The junction area is part of the second region, the crystallized doped portion is the portion of the second semiconductor doped layer located on the junction area, and the portion of the second semiconductor doped layer not located on the junction area is the amorphized doped portion.

4. The solar cell according to claim 1, characterized in that The interface region includes a portion of the first region and a portion of the second region; The crystallized doping portion includes a first crystallized doping portion and a second crystallized doping portion, the first crystallized doping portion is a portion of the first semiconductor doping layer located on the junction area, and the second crystallized doping portion is a portion of the second semiconductor doping layer located on the junction area; the portion of the first semiconductor doping layer not located on the junction area is a first amorphized doping portion, and the portion of the second semiconductor doping layer not located on the junction area is a second amorphized doping portion.

5. The solar cell according to any one of claims 1 to 4, characterized in that The first crystallization rate is 10% to 40%, and the second crystallization rate is 0; and / or the grain size in the crystallized doping part is 5nm to 30nm.

6. The solar cell according to any one of claims 1 to 4, characterized in that: The ratio of the area of ​​the boundary area to the area of ​​the first area is 1% to 30%.

7. The solar cell according to any one of claims 1 to 4, characterized in that Also includes: a conductive layer, at least located on a portion of the surface of the first passivation structure away from the first surface, and at least located on a portion of the surface of the second passivation structure away from the first surface; A first electrode is disposed on a side of the conductive layer located on the first region away from the first passivation structure; A second electrode is disposed on a side of the conductive layer located on the second region away from the second passivation structure; The insulating layer is located on a portion of the surface of the first passivation structure away from the first surface, and the second passivation structure is also located on a surface of the insulating layer away from the first passivation structure, and there is a gap between the second passivation structure located on the surface of the insulating layer away from the first passivation structure and the first electrode.

8. The solar cell according to any one of claims 1 to 4, characterized in that At least part of the junction area also has a crystallized passivation portion, which is a portion of at least one of the first passivation layer and the second passivation layer. The crystallized passivation portion has a third crystallization rate, and the first passivation layer and the second passivation layer not located on the junction area have a fourth crystallization rate, and the third crystallization rate is greater than the fourth crystallization rate.

9. A method for preparing a solar cell, characterized in that: include: Providing a substrate, the substrate having a first surface and a second surface opposite to each other, the first surface comprising first areas and second areas alternately arranged along a first direction; An initial first passivation structure and an initial second passivation structure are sequentially formed on the first surface, the initial first passivation structure is located on the first region, the initial first passivation structure includes an initial first passivation layer and an initial first semiconductor doping layer stacked along a second direction, the initial second passivation structure is at least located on the second region, the initial second passivation structure includes an initial second passivation layer and an initial second semiconductor doping layer stacked along the second direction, and the doping type of the initial first semiconductor doping layer is different from the doping type of the initial second semiconductor doping layer; The first surface further includes a junction area, the junction area includes a portion of at least one of the first area and the second area, and a sidewall of the initial first semiconductor doping layer and a sidewall of the initial second semiconductor doping layer are in contact with each other at the junction area; The preparation method also includes: performing laser crystallization treatment on a portion of at least one of the first semiconductor doping layer and the second semiconductor doping layer located on the junction area to transform the initial first passivation structure into a first passivation structure, transform the initial second passivation structure into a second passivation structure, and form a crystallized doping portion on at least a portion of the junction area.

10. A photovoltaic module, characterized in that: include: A battery string, formed by connecting a plurality of solar cells according to any one of claims 1 to 8, or by connecting a plurality of solar cells formed by the preparation method according to claim 9; A packaging film, used to cover the surface of the battery string; The cover plate is used to cover the surface of the packaging film facing away from the battery string.

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